Multi-charged-particle beam writing apparatus and multi-charged-particle beam writing method

ABSTRACT

Provided is a multi-charged-particle beam writing apparatus including: an emitter emitting a charged particle beam; a first shaping aperture array substrate having a plurality of first apertures and forming first multiple beams by passing a part of the charged particle beam through the first apertures, respectively; a second shaping aperture array substrate having second apertures formed at positions corresponding to the respective first apertures and forming second multiple beams by passing at least a part of each of the first multiple beams through corresponding the second apertures, respectively; a blanking aperture array having third apertures formed at positions corresponding to the respective second apertures and including blankers disposed in the respective third apertures to perform blanking deflection on the respective beams of the corresponding second multiple beams; a movable mechanism moving at least one of the first shaping aperture array substrate and the second shaping aperture array substrate; and a controller controlling the movable mechanism.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority fromJapanese Patent Applications No. 2019-022938, filed on Feb. 12, 2019,the entire contents of which are incorporated herein by reference.

FIELD OF THE INVENTION

Embodiments relate to a multi-charged-particle beam writing apparatusand a multi-charged-particle beam writing method and relates to a methodand an apparatus for adjusting sizes and current amounts of individualbeams, for example, in multiple beams writing.

BACKGROUND OF THE INVENTION

A lithography technique that is responsible for progress inminiaturization of semiconductor devices is an extremely importantprocess which uniquely generates patterns among semiconductormanufacturing processes. In recent years, with high integration of LSI,a circuit line width required for semiconductor devices has becomenarrow. Herein, an electron beam writing technique has an essentiallyexcellent resolution, and thus, the writing of a mask pattern has beenperformed by using an electron beam to a mask blank.

For example, there is a writing apparatus using multiple beams. Ascompared with the case of writing with a single electron beam,irradiation with many beams can be performed at once by using themultiple beams, so that the throughput can be greatly improved. In sucha multi-beam type writing apparatus, for example, multiple beams areformed from an electron beam emitted from an electron gun through a maskhaving a plurality of holes; each beam is blanking-controlled, so thatthe respective beams that have not been shielded are reduced by anoptical system; and the mask image is reduced and deflected by adeflector, so that a desired position on the sample is irradiated.

An important issue in the writing with the multiple beams is to performthe writing by individually controlling characteristics such as sizesand current amounts of the respective beams while maintaining highthroughput. Each beam can be adjusted by adjusting conditions of lensesof a reduced lens, an objective lens, and the like described later.However, it takes time to adjust the conditions of the lenses, and thus,there is a problem that it is difficult to improve the throughput of thewriting.

If a current amount of each beam is increased, the writing time isshortened, and thus, it is possible to improve the throughput. However,charged particles contained in each beam have the same polarity charges.For example, in the case of using electron beams as charged particlebeams, electrons contained in each electron beam has negative charges.For this reason, if the current amount is increased, due to the Coulombeffect originated from the Coulomb force, the repulsion of the electronbeams with each other is increased. Therefore, it is difficult to writea predetermined mask pattern, and thus, there is a problem that thewriting accuracy is deteriorated.

Therefore, it is considered that, in the case of writing a mask patternnot requiring a high writing accuracy, the writing is performed at ahigh speed by increasing the current amount; and in the case of writinga mask pattern requiring a high writing accuracy, the writing isperformed at a high accuracy by decreasing the current amount. However,in this case, it is required to switch the current density for each maskpattern. Since the switching of the current density involves theadjustment of each beam by adjustment of the conditions of the lensesdescribed above or the like, there is also a problem that it isdifficult to improve the throughput of the writing.

An aspect of embodiments is to provide a multi-charged-particle beamwriting apparatus and a multi-charged-particle beam writing methodcapable of adjusting sizes and current amounts of charged particle beamswithout readjustment of lens conditions.

SUMMARY OF THE INVENTION

According to an aspect of embodiments, there is provided amulti-charged-particle beam writing apparatus including: an emitteremitting a charged particle beam; a first shaping aperture arraysubstrate having a plurality of first apertures and forming firstmultiple beams by passing a part of the charged particle beam throughthe first apertures, respectively; a second shaping aperture arraysubstrate having second apertures formed at positions corresponding tothe respective first apertures and forming second multiple beams bypassing at least a part of each of the first multiple beams throughcorresponding the second apertures, respectively; a blanking aperturearray having third apertures formed at positions corresponding to therespective second apertures and including blankers disposed in therespective third apertures to perform blanking deflection on therespective beams of the corresponding second multiple beams; a movablemechanism moving at least one of the first shaping aperture arraysubstrate and the second shaping aperture array substrate; and acontroller controlling the movable mechanism.

According to an aspect of embodiments, there is provided amulti-charged-particle beam writing method including: forming firstmultiple beams by allowing portions of a charged particle beam to passthrough a plurality of first apertures of a first shaping aperture arraysubstrate, respectively; forming second multiple beams by allowing atleast portions of respective beams of the first multiple beams to passthrough a plurality of second apertures of a second shaping aperturearray substrate formed at positions corresponding to the firstapertures, respectively; performing blanking deflection on therespective beams of the second multiple beams; performing measurement oftransmission current of the second multiple beams on each ofpredetermined divided regions of the blanking aperture array; and movingat least one of the first shaping aperture array substrate and thesecond shaping aperture array substrate on the basis of a result of thecurrent measurement.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a conceptual diagram illustrating a configuration of a writingapparatus according to an embodiment;

FIG. 2 is a conceptual diagram illustrating a configuration of alimiting aperture array substrate, a first shaping aperture arraysubstrate, and a second shaping aperture array substrate in theembodiment;

FIG. 3 is a cross-sectional view illustrating a configuration of ablanking aperture array mechanism in the embodiment;

FIG. 4 is a conceptual top view illustrating a portion of theconfiguration of the blanking aperture array mechanism in a membraneregion in the embodiment;

FIG. 5 is a diagram illustrating an example of an individual blankingmechanism according to the embodiment;

FIGS. 6A to 6B are conceptual views illustrating an example of a writingoperation in the embodiment;

FIG. 7 is a flowchart of a multi-charged-particle beam writing methodaccording to the embodiment;

FIG. 8 is a flowchart of a multi-charged-particle beam writing methodrelated to adjustment of multiple charged particle beams in theembodiment;

FIGS. 9A to 9C are conceptual diagrams illustrating an example of amethod of adjusting multiple charged particle beams in the embodiment;

FIG. 10 is an example of an origin map win the embodiment;

FIG. 11 is a conceptual diagram illustrating an example of a writingoperation on a sample in the embodiment; and

FIG. 12 is a view illustrating an example of an irradiation region ofmultiple beams and writing target pixels in the embodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In the following embodiment, a configuration using an electron beam asan example of a charged particle beam will be described. The chargedparticle beam is not limited to the electron beam, but a beam using acharged particle such as an ion beam may be used.

Embodiment

FIG. 1 is a conceptual diagram illustrating a configuration of a writingapparatus according to an embodiment. In FIG. 1, a writing apparatus 100includes a writing mechanism 150 and a control system circuit 160. Thewriting apparatus 100 is an example of a multi-charged-particle beamwriting apparatus. The writing mechanism 150 includes an electron lensbarrel 102 (multi-electron-beam column) and a writing chamber 103. Inthe electron lens barrel 102, an electron gun 201, an illumination lens202, a limiting aperture array substrate 220, a first shaping aperturearray substrate 230, a second shaping aperture array substrate 240, ablanking aperture array 250, a reduction lens 205, a limiting aperturemember 206, an objective lens 207, a main deflector 208 (firstdeflector), and a sub-deflector 209 (second deflector) are disposed. Inaddition, the electron gun 201 is an example of an emitter.

The limiting aperture array substrate 220 has a plurality of fourthapertures 222. The first shaping aperture array substrate 230 has aplurality of first apertures 232. The second shaping aperture arraysubstrate 240 has a plurality of second apertures 242. The blankingaperture array 250 has a plurality of third apertures 252. The firstshaping aperture array substrate 230 and the second shaping aperturearray substrate 240 are connected to the ground potential by wires (notillustrated).

The first shaping aperture array substrate 230 and the second shapingaperture array substrate 240 are used for shaping the multiple beams.The blanking aperture array 250 is used for deflecting a portion or allof the multiple beams. The limiting aperture array substrate 220suppresses electron beams 200 that are not used in writing from strikingthe first shaping aperture array substrate 230. When the electron beamsstrike the first shaping aperture array substrate 230, the first shapingaperture array substrate 230 generates heat. Since the first shapingaperture array substrate 230 is thermally expanded by the heatgeneration, the shapes and disposition of the first apertures 232 areshifted, and thus, there occur shifts in current amounts, shapes,writing positions, and the like of the respective beams of the multiplebeams to be formed. Therefore, the limiting aperture array substrate 220is provided so as to suppress the heat generation of the first shapingaperture array substrate 230.

The limiting aperture array substrate 220 is, for example, a siliconsubstrate. In this case, it is preferable to suppress excessive heatgeneration and localized heat generation of the limiting aperture arraysubstrate 220 by using, for example, a silicon substrate doped withimpurities having a large film thickness.

The first shaping aperture array substrate 230 and the second shapingaperture array substrate 240 are, for example, semiconductor substratesdoped with impurities. In order to accurately form the first apertures232 and the second apertures 242, it is preferable to use a silicon (Si)substrate.

Herein, for the convenience of description, the vertical direction isdefined as a Z direction, one direction of the horizontal directionsperpendicular to the vertical direction is defined as an X direction,and the horizontal direction perpendicular to the Z and X directions isdefined as a Y direction. A first movable mechanism (movable mechanism)2 for moving the limiting aperture array substrate 220 and the firstshaping aperture array substrate 230 in a plane parallel to an XY planeand a second movable mechanism 258 for moving the blanking aperturearray 250 in a plane parallel to the XY plane are provided in theelectron lens barrel 102. In addition, the first movable mechanism 2 maybe a movable mechanism for moving only the first shaping aperture arraysubstrate 230.

In the multi-charged-particle beam writing apparatus and themulti-charged-particle beam writing method according to an aspect ofembodiments, by relatively moving the first shaping aperture arraysubstrate 230 in parallel to the second shaping aperture array substrate240 in the XY plane, the overlapping manner of the first apertures 232and the second apertures 242 in the vertical direction is changed, sothat the size and current amount of the charged particle beam can beadjusted.

An XY stage 105 is disposed in the writing chamber 103. A beamabsorption electrode (Faraday cup 211) for measuring the current of theelectron beam is disposed on the XY stage 105. In addition, at the timeof writing, a sample (not illustrated) such as a mask blank coated withresist which is to be a writing target substrate is disposed on the XYstage 105. Herein, the sample includes an exposure mask at the time ofmanufacturing a semiconductor device, a semiconductor substrate (siliconwafer) in which a semiconductor device is to be manufactured, or thelike. Furthermore, a mirror 210 for position measurement of the XY stage105 is disposed on the XY stage 105. The XY stage 105 is movable in theXY plane.

The control system circuit 160 includes a control computer 110, a memory112, a deflection control circuit 130, digital-to-analog converter (DAC)amplifier 132 and 134, a stage position detector 139, a writing datastorage memory 140, an irradiation time correction amount storage memory142, an origin map storage memory 144, and a current map storage memory146. The control computer 110, the memory 112, the deflection controlcircuit 130, the DAC amplifier 132 and 134, the stage position detector139, the writing data storage memory 140, the irradiation timecorrection amount storage memory 142, the origin map storage memory 144,and the current map storage memory 146 are connected to each other via abus (not illustrated).

The writing data storage memory 140, the irradiation time correctionamount storage memory 142, the origin map storage memory 144, and thecurrent map storage memory 146 include, for example, a recording mediumsuch as a magnetic disk device, a magnetic tape device, an FD, a readonly memories (ROM), or a solid state drive (SSD).

The DAC amplifier 132 and 134 and the blanking aperture array 250 areconnected to the deflection control circuit 130. The output of the DACamplifier 132 is connected to the sub-deflector 209. The output of theDAC amplifier 134 is connected to the main deflector 208. The stageposition detector 139 irradiates the mirror 210 on the XY stage 105 withlaser light and receives the reflected light from the mirror 210. Then,the position of the XY stage 105 is measured by utilizing the principleof laser interference using information of such reflected light.

A writing controller 56, an aperture movement controller (controller)58, an irradiation time correction amount calculator 60, and atransmission current measurement circuit 62 are provided in the controlcomputer 110. The writing controller 56, the aperture movementcontroller (controller) 58, the irradiation time correction amountcalculator 60, and the transmission current measurement circuit 62includes a processing circuit. Such processing circuit includes, forexample, an electric circuit, a computer, a processor, a circuit board,a quantum circuit, or a semiconductor device. In addition, a commonprocessing circuit (same processing circuit) may be used, or differentprocessing circuits (separate processing circuits) may be used for thewriting controller 56, the aperture movement controller (controller) 58,the irradiation time correction amount calculator 60, and thetransmission current measurement circuit 62. Information input to oroutput from information in operation in the writing controller 56, theaperture movement controller (controller) 58, the irradiation timecorrection amount calculator 60, and the transmission currentmeasurement circuit 62 can be stored in the memory 112 in each case.

The aperture movement controller 58 is connected to the first movablemechanism 2 and the second movable mechanism 258. The aperture movementcontroller 58 can move the limiting aperture array substrate 220, thefirst shaping aperture array substrate 230, and the blanking aperturearray 250 by using the first movable mechanism 2 and the second movablemechanism 258.

In addition, the writing data is input from the outside of the writingapparatus 100 and is stored in the writing data storage memory 140. Inthe writing data, typically information of a plurality of figurepatterns for writing is defined. Specifically, figure code, coordinates,size, and the like are defined for each figure pattern. Alternatively,figure code, coordinates of each vertex, and the like are defined foreach figure pattern.

Herein, FIG. 1 illustrates a configuration required for describing theembodiments. The writing apparatus 100 may be provided with anyconfiguration other than the required configuration typically.

FIG. 2 is a conceptual diagram illustrating a configuration of the firstshaping aperture array substrate 230 in the embodiment. Longitudinal (ydirection) p columns x transverse (x direction) q columns (p, q≥2) holes(first apertures 232) are formed in a matrix shape at a predetermineddisposition pitch. In FIG. 2, for example, the first apertures 232 ofthe 512×512 columns in the longitudinal and transverse directions (inthe x and y directions) are formed. The first apertures 232 are formedtogether in a rectangular shape with the same dimensions. Alternatively,the first apertures 232 may be circular with the same diameter. Byallowing portions of the electron beam 200 to pass through the firstapertures 232, respectively, the multiple beams 20 are formed. Inaddition, a method of disposing the first apertures 232 is not limitedto a case where the longitudinal and transverse apertures are disposedin a grid as illustrated in FIG. 2. For example, the holes of the k-thstage column and the (k+1)-th stage column in the longitudinal direction(y direction) may be disposed to be shifted by a distance “a” in thetransverse direction (x direction). Similarly, the holes of the (k+1)-thstage column and the (k+2)-th stage column in the longitudinal direction(y direction) may be disposed to be shifted by a distance “b” in thetransverse direction (x direction).

In addition, although FIG. 2 illustrates the configuration of the firstshaping aperture array substrate 230 and the first apertures 232, theconfiguration of the second shaping aperture array substrate 240 and thesecond apertures 242 and the configuration of the limiting aperturearray substrate 220 and the fourth apertures 222 are also similar. Forexample, the number of first apertures 232, the number of secondapertures 242, the number of third apertures 252, and the number offourth apertures 222 are equal. On the other hand, the shapes of thefirst apertures 232 and the shapes of second apertures 242 may be thesame or may be different. By allowing the shapes of the first apertures232 and the shapes of the second apertures 242 to be different, it ispossible to form multiple beams having various shapes.

Herein, it is preferable that the sizes of the fourth apertures 222 arelarger than the sizes of the first apertures 232 corresponding to therespective beams of the multiple beams formed by the fourth apertures222. If the sizes of the fourth apertures 222 are equal to or smallerthan the sizes of the first apertures 232 corresponding to therespective beams of the multiple beams formed by the fourth apertures222, the multiple beams smaller than the sizes of the fourth apertures222 cannot be formed, so that the degree of freedom of the formation ofthe multiple beams by the first shaping aperture array substrate 230 andthe second shaping aperture array substrate 240 is decreased. Asdescribed above, the limiting aperture array substrate 220 in whichfourth apertures 222 are provided is intended to suppress the surpluselectron beams that are not used for writing from striking the firstshaping aperture array substrate 230. Therefore, it is preferable thatthe fourth apertures 222 are larger than the first apertures 232 so asto suppress surplus electron beams from striking the first shapingaperture array substrate 230 and not to impair a degree of freedom ofthe electron beam shaping by the first shaping aperture array substrate230 and the second shaping aperture array substrate 240.

FIG. 3 is a cross-sectional view illustrating a configuration of theblanking aperture array 250 in the embodiment. FIG. 4 is a conceptualtop view illustrating a portion of the configuration of the blankingaperture array 250 in the membrane region in the embodiment. Inaddition, in FIGS. 3 and 4, the positional relationships among thecontrol electrode 254, the counter electrode 256, the control circuit41, and the pad 43 are not described to match with each other. Inaddition, the numbers of the third apertures 252, the control electrodes254, the counter electrodes 256, and the control circuits (logiccircuits) 41 may be different from those illustrated in FIGS. 3 and 4.In addition, the number of the first apertures 232 illustrated in FIG. 2and the number of the third apertures 252 illustrated in FIGS. 3 and 4are not matched.

In the blanking aperture array 250, as illustrated in FIG. 3, theblanking aperture array substrate 251 made of Si (silicon) or the likeis disposed on the blanking aperture array support base 253. Theblanking aperture array substrate 251 is, for example, a semiconductorsubstrate. The central portion of the blanking aperture array substrate251 is, for example, scraped thinly from the back surface side to beprocessed into a membrane region 330 (first region) having a thin filmthickness h. The periphery surrounding the membrane region 330 is anouter peripheral region 332 (second region) having a large thickness H.The upper surface of the membrane region 330 and the upper surface ofthe outer peripheral region 332 are formed so as to be at the sameheight position or at substantial height positions. The blankingaperture array substrate 251 is held on the blanking aperture arraysupport base 253 at the back surface of the outer peripheral region 332.The central portion of the blanking aperture array support base 253 isopened, and the position of the membrane region 330 is positioned in theopened region of the blanking aperture array support base 253.

The third apertures 252 for passage of the respective beams of themultiple beams are disposed at the positions corresponding to the fourthapertures 222 of the limiting aperture array substrate 220, the firstapertures 232 of the first shaping aperture array substrate 230, and thesecond apertures 242 of the second shaping aperture array substrate 240in the membrane region 330. In addition, in other words, the thirdapertures 252 through which the respectively corresponding beams of themultiple beams using the electron beam pass are formed in an array inthe membrane region 330 of the blanking aperture array substrate 251.

Then, a plurality of electrode pairs having two electrodes at positionsfacing each other and interposing the corresponding third apertures 252of the third apertures 252 are disposed on the membrane region 330 ofthe blanking aperture array substrate 251, respectively. Specifically,as illustrated in FIGS. 3 and 4, sets (blankers: blanking deflectors) ofthe control electrode 254 and the counter electrode 256 for blankingdeflection and interposing the corresponding third apertures 252 aredisposed at positions in the vicinity of each of the third apertures 252on the membrane region 330, respectively. In addition, the controlcircuit 41 (logic circuit) for applying a deflection voltage to thecontrol electrode 254 for each of the third apertures 252 is disposed inthe vicinity of each of the third apertures 252 on the membrane region330 in the blanking aperture array substrate 251. The counter electrode256 is connected to the ground potential.

In addition, as illustrated in FIG. 4, each control circuit 41 isconnected to parallel wiring of n bits (for example, 10 bits) for thecontrol signal. Besides other n-bit parallel wires for the controlsignal, clock signal lines and wires for the read signal, the shotsignal, and the power supply are connected to each control circuit 41.The clock signal lines and wires for the read signal, the shot signal,and the power supply may be configured by using a portion of theparallel wires. For each beam constituting the multiple beams, anindividual blanking mechanism 47 is configured with the controlelectrode 254, the counter electrode 256, and the control circuit 41. Inaddition, in the example of FIG. 3, the control electrode 254, thecounter electrode 256, and the control circuit 41 are disposed in themembrane region 330 having a small film thickness of the blankingaperture array substrate 251. In addition, the disposition of thecontrol electrode 254, the counter electrode 256, and the controlcircuit 41 is not limited to that illustrated in FIGS. 3 and 4.

In addition, the control circuits 41 formed in an array shape on themembrane region 330 are grouped, for example, by the same row or thesame column, the control circuits 41 in the group are connected inseries as illustrated in FIG. 4. Then, a signal from the pad 43 disposedfor each group is transmitted to the control circuits 41 in the group.Specifically, a shift register (not illustrated) is disposed in each ofthe control circuits 41, and for example, shift registers in the controlcircuits 41 for the beams, for example, in the same row among the p×qmultiple beams are connected in series. Then, for example, the controlsignal of the beam in the same row of the p×q multiple beams istransmitted in series, and, for example, the control signal for eachbeam is stored in the corresponding control circuit 41 with p times ofthe clock signal.

FIG. 5 is a diagram illustrating an example of the individual blankingmechanism 47 according to the embodiment. In FIG. 5, the amplifier 46(an example of a switching circuit) is disposed in the control circuit41. In the example of FIG. 5, a complementary MOS (CMOS) invertercircuit is disposed as an example of the amplifier 46. Then, the CMOSinverter circuit is connected to a positive potential (Vdd: blankingpotential: first potential) (for example, 5 V) and a ground potential(GND: second potential). The output line (OUT) of the CMOS invertercircuit is connected to the control electrode 254. On the other hand,the counter electrode 256 is applied with the ground potential. Then, aplurality of control electrodes 254 to which the blanking potential andthe ground potential are switchably applied are disposed at thepositions facing the counter electrodes 256 corresponding to each of theplurality of counter electrodes 256 with the third apertures 252corresponding to each of the plurality of third apertures 252 interposedon the substrate 31.

As a control signal, one of an L (low) potential (for example, groundpotential) lower than a threshold voltage and a H (high) potential (forexample, 1.5 V) higher than a threshold voltage is applied to the input(IN) of the CMOS inverter circuit. In the embodiment, in the state wherethe L potential is applied to the input (IN) of the CMOS invertercircuit, the output (OUT) of the CMOS inverter circuit becomes thepositive potential (Vdd), and thus, the corresponding electron beam(E-beam) is deflected by the electric field due to the potentialdifference from the ground potential of the counter electrode 256, sothat the beam is controlled to be in the beam OFF by being shielded bythe limiting aperture member 206. On the other hand, in the state(active state) where the H potential is applied to the input (IN) of theCMOS inverter circuit, the output (OUT) of the CMOS inverter circuitbecomes the ground potential, and thus, the corresponding the electronbeam (E-beam) is not deflected due to the elimination of the potentialdifference from the ground potential of the counter electrode 256, sothat the beam is controlled to be in the beam ON by passing through thelimiting aperture member 206.

The electron beam (E-beam) passing through each passage hole isdeflected by a voltage applied to two electrodes of the controlelectrodes 254 and the counter electrode 256 to be independently inpairs. The blanking control is performed by the deflection.Specifically, the set of the control electrode 254 and the counterelectrode 256 respectively individually performs blanking deflection onthe corresponding electron beams of the multiple beams by the potentialsto be switched by the CMOS inverter circuits which become thecorresponding switching circuits. In this manner, a plurality ofblankers perform the blanking deflection on the corresponding beamsamong the multiple beams passing through the second apertures 242 of thesecond shaping aperture array substrate 240.

FIGS. 6A to 6B are conceptual views illustrating disposition of thelimiting aperture array substrate 220, the first shaping aperture arraysubstrate 230, the second shaping aperture array substrate 240, and theblanking aperture array 250 and a supporting method in the embodiment.FIG. 6A is a schematic cross-sectional view of the limiting aperturearray substrate 220, the first shaping aperture array substrate 230, thesecond shaping aperture array substrate 240, and the blanking aperturearray 250 in a plane parallel to the YZ plane. FIG. 6B is a schematicview illustrating disposition of the first shaping aperture arraysubstrate 230, first support bases 4, first support fittings 6, thesecond shaping aperture array substrate 240, second support bases 14,and second support fittings 16 when viewed upwardly from the lower sidein the vertical direction.

In addition, in FIGS. 6A to 6B, the shapes, disposition, and numbers ofthe fourth apertures 222, the first apertures 232, the second apertures242, and third apertures 252 do not match with the illustration of FIGS.1, 2, 3, and 4. In addition, the control circuit 41, the controlelectrode 254, and the counter electrode 256 illustrated in FIGS. 3 and4 are omitted in illustration.

The centers of the first support bases 4 are opened. Then, the limitingaperture array substrate 220 is disposed on the first support base 4 sothat the fourth apertures 222 are disposed on the opened portions of thefirst support bases 4. The electron beam 200 emitted from the electrongun 201 illuminates the entire fourth apertures 222 of the limitingaperture array substrate 220 substantially vertically by theillumination lens 202. Then, the electron beam 200 passes through eachof the fourth apertures 222, so that the multiple beams 20 (thirdmultiple beams) are formed. The shape of the multiple beams 20 isobtained by reflecting the shape of the plurality of fourth apertures222 and is, for example, a rectangular shape.

As illustrated in FIG. 6A, the first shaping aperture array substrate230 is fixed below the first support base 4 by using, for example, thefirst support fitting 6. In this case, the first apertures 232 aredisposed below the portion of the first support base 4 which is opened.Furthermore, the first apertures 232 are disposed to be aligned with thetrajectories of the respective beams of the multiple beams 20. A part ofthe respective beams of the multiple beams 20 pass through the firstapertures 232, respectively, so that the multiple beams (first multiplebeams) are formed.

By allowing the first movable mechanism 2 to move the first support base4, the limiting aperture array substrate 220 and the first shapingaperture array substrate 230 can be moved in the XY plane. The firstmovable mechanism 2 may be a “roller” having a cylindrical cross sectionas illustrated in FIG. 6A. However, it is preferable to use an actuatorsuch as a piezoelectric element, by which it is possible to move with ahigh accuracy. In addition, the limiting aperture array substrate 220may not move in the XY plane by the first movable mechanism 2. Since thelimiting aperture array substrate 220 is directly irradiated with theelectron beam as described above, the heat generation amount is large.This is because, if the limiting aperture array substrate 220 is notassumed to be moved by a movable mechanism, the cooling is facilitated.

As illustrated in FIG. 6A, the second shaping aperture array substrate240 is disposed below the first shaping aperture array substrate 230.The second apertures 242 are disposed to be aligned with thetrajectories of the respective beams of the multiple beams 21 (firstmultiple beams). Then, at least part of each of the multiple beams 21pass through the corresponding the second apertures, respectively, sothat the multiple beams (second multiple beams) are formed.

As illustrated in FIG. 6B, in a case where the first shaping aperturearray substrate 230 and the second shaping aperture array substrate 240has, for example, a rectangular shape, it is preferable that thelongitudinal direction of the first shaping aperture array substrate 230is disposed parallel to the X direction, and the longitudinal directionof the second shaping aperture array substrate 240 is disposed parallelto the Y direction. Accordingly, it is preferable that the first shapingaperture array substrate 230 is supported at the end in the longitudinaldirection of the first shaping aperture array substrate 230 by using thefirst support base 4 and the first support fitting 6, and the secondshaping aperture array substrate 240 is supported at the end in thelongitudinal direction of the second shaping aperture array substrate240 by using the second support base 14 and the second support fitting16. The gap in the Z direction between the first shaping aperture arraysubstrate 230 and the second shaping aperture array substrate 240 ispreferably narrow for example, about 1 mm in order to increase theaccuracy at the end of the multiple beams 22 (second multiple beams) tobe described later, but this is too narrow for a human to put a hand in.For this reason, it is very difficult to access the gap between thefirst shaping aperture array substrate 230 and the second shapingaperture array substrate 240. Therefore, the longitudinal direction ofthe first shaping aperture array substrate 230 and the longitudinaldirection of the second shaping aperture array substrate 240 aredisposed so as to be perpendicular to each other as in FIG. 6B. In thismanner, it is possible to access the gap between the first shapingaperture array substrate 230 and the second shaping aperture arraysubstrate 240 to some extent from the X direction as well as from the Ydirection. In addition, the region 244 of the second shaping aperturearray substrate 240 is a region in which the second apertures 242 aredisposed.

In addition, the second shaping aperture array substrate 240 may bemoved in the XY plane by the movable mechanism or the like.

The blanking aperture array 250 is disposed below the second shapingaperture array substrate 240. The third apertures 252 are disposed to bealigned with the trajectories of the respective beams of the multiplebeams 22. The blankers deflect the respective beams of the multiplebeams 22 individually passing (performs blanking deflection).

The multiple beams 22 passing through the blanking aperture array 250 isreduced by the reduction lens 205 and travel toward the hole at thecenter formed on the limiting aperture member 206. Herein, the electronbeam deflected by the blanker is shifted in position from the hole atthe center of the limiting aperture member 206, so that the electronbeam is shielded by the limiting aperture member 206. On the other hand,the electron beam that is not deflected by the blanker passes throughthe hole at the center of the limiting aperture member 206. By ON/OFF ofthe individual blanking mechanism, blanking control is performed, sothat ON/OFF of the beam is controlled. Thus, the limiting aperturemember 206 shields the respective beams deflected so as to be in thestate of the beam OFF by the individual blanking mechanism 47. Then, foreach beam, the beam corresponding to one shot is formed by the beambeing formed from the time of becoming the beam ON to the time of beingthe beam OFF and passing through the limiting aperture member 206.

The multiple beams 22 passing through the limiting aperture member 206are focused by the objective lens 207 to become a pattern image with adesired reduction ratio, and the respective beams (entire multiple beams22) passing through the limiting aperture member 206 are deflectedcollectively in the same direction by the main deflector 208 and thesub-deflector 209. Then, the interior of the Faraday cup 211 isirradiated. In a case where the sample is disposed on the XY stage 105,the respective irradiation positions of the sample are irradiated.

FIG. 7 is a flowchart of a multi-charged-particle beam writing methodaccording to the embodiment. FIG. 8 is a flowchart of amulti-charged-particle beam writing method related to adjustment ofmultiple charged particle beams in the embodiment. Hereinafter, thedescription will be made with reference to both FIGS. 7 and 8.

First, first coarse position adjustment is performed (S10). This isperformed because, in the initial setting of the limiting aperture arraysubstrate 220, the first shaping aperture array substrate 230, thesecond shaping aperture array substrate 240, and the blanking aperturearray 250, it is unknown whether or not the fourth apertures 222, thefirst apertures 232, the second apertures 242, and the third apertures252 are aligned in the vertical direction to allow the multiple beams tobe capable of passing through. For this reason, without emitting theelectron beams 200 from the electron gun 201, the coarse positionadjustment is performed. For example, it is checked by using an opticalmicroscope or the like whether or not there is a portion through whichthe fourth apertures 222, the first apertures 232, the second apertures242, and third apertures 252 pass in the vertical direction. Inaddition, the position alignment of the limiting aperture arraysubstrate 220, the first shaping aperture array substrate 230, thesecond shaping aperture array substrate 240, and the blanking aperturearray 250 may be performed at a degree of visual alignment.

Then, the electron beam 200 (an example of a charged particle beam) isemitted from the electron gun 201. Thus, in particular, the limitingaperture array substrate 220 is heated. In addition, the first shapingaperture array substrate 230, the second shaping aperture arraysubstrate 240, and the blanking aperture array 250 are also heated.Since a change in shapes and dimensions of the apertures due to thermalexpansion of the aperture involved with the heating occurs, a change inshapes, sizes, and current amounts of the multiple beams occurs.Therefore, the first shaping aperture array substrate 230, the secondshaping aperture array substrate 240, and the blanking aperture array250 are in a stand-by state until the temperature is stable by theheating (S20).

Next, second coarse position adjustment is performed (S30). Thisadjustment is intended to adjust the multiple beams formed by thelimiting aperture array substrate 220, the first shaping aperture arraysubstrate 230, and the second shaping aperture array substrate 240 topass through the blanking aperture array 250.

Then, shaping adjustment is started (S40). First, the blankingdeflection using the blankers is performed so that the multiple beams 22passing through the blanking aperture array 250 reach the Faraday cup211 with respect to a predetermined region (predetermined dividedregion) of, for example, about 16×16 columns or about 32×32 columnsamong the 512×512 columns in the longitudinal and transverse directions(the x and y directions) illustrated in FIG. 2 and the multiple beams 22do not reach the Faraday cup 211 with respect to the other regions(S42).

Next, for alignment origin measurement, the transmission currentmeasurement circuit 62 performs measurement of the transmission currentof the multiple beams passing through the predetermined divided regiondescribed above without being subjected to the blanking deflection (S44)by using the Faraday cup 211. The measurement of the transmissioncurrent is performed, while moving, for example, the first shapingaperture array substrate 230 or the second shaping aperture arraysubstrate 240. FIGS. 9A to 9C illustrate conceptual views of an exampleof a method of adjusting the multiple charged particle beams in theembodiment. One of the first apertures 232 and one of the secondapertures 242 are illustrated in FIGS. 9A and 9B. Herein, both the firstapertures 232 and the second apertures 242 are assumed to have a squareshape having the same size. When the first shaping aperture arraysubstrate 230 is moved in the Y direction by using the first movablemechanism 2, the overlapped portion between one of the first apertures232 and one of the second apertures 242 is changed as viewed in the Zdirection. Thus, accordingly, the current amounts of the respectivebeams of the multiple beams passing through both one of the firstapertures 232 and one of the second apertures 242 are changed.

Further, in FIG. 9A, one side of the square of one of the firstapertures 232 in the left side of the paper surface and one side of thesquare of one of the second apertures 242 in the left side of the papersurface are shifted from each other. On the other hand, in FIG. 9B, oneside of the square of one of the first apertures 232 in the left side ofthe paper surface and one side of the square of one of the secondapertures 242 in the left side of the paper surface are substantiallyoverlapped with each other. Furthermore, one side of the square of oneof the first apertures 232 in the right side of the paper surface andone side of the square of one of the second apertures 242 in the rightside of the paper surface are substantially overlapped with each other.For this reason, a larger current amount of the multiple beams isobtained from the case of disposition illustrated in FIG. 9B.

FIG. 9C illustrates the changes in the current amounts the respectivebeams of the multiple beams passing through both one of the firstapertures 232 and one of the second apertures 242 when the first shapingaperture array substrate 230 moved in the Y direction. For the case ofFIG. 9C, a larger amount of current can be obtained. If similaroperations are also performed in the X direction, it is possible toobtain the relative position (alignment position) of the first shapingaperture array substrate 230 and the second shaping aperture arraysubstrate 240 at which the largest current amount in a predetermineddivided region can be obtained. In the above, although a series ofoperations are performed with respect to one of the first apertures 232and one of the second apertures 242, it is preferable to determine thealignment position while measuring the current amounts of the multiplebeams by the Faraday cup 211 all at once with respect to a predeterminedregion of for example, about 16×16 columns or about 32×32 columns. Thiswork is carried out for all the divided regions (S46).

Next, the origin map is created on the basis of the measurement resultobtained in (S44) (S48), and a relative positional relationship betweenthe first shaping aperture array substrate 230 and the second shapingaperture array substrate 240 is determined (S50). The origin map createdis stored, for example, in the origin map storage memory 144. FIG. 10 isan example of the origin map in the embodiment. Although a total of 25circles 334 are illustrated in FIG. 10, each one of the circles 334indicates the position which is irradiated with the respective one ofthe multiple beams through the circle. In addition, the grid of a totalof 16 squares illustrates approximate positions. Among the total of 25circles, the center of a circle 334 a illustrated in the central portionis substantially coincident with the point at which the square grid isformed. On the other hand, as the centers of the other circles 334 arefarther from the central circle 334 a, the shift from the point wherethe square grid is formed becomes large. This shift is due to thedifference between the thermal expansion of the first shaping aperturearray substrate 230 and the thermal expansion of the second shapingaperture array substrate 240. Even though the limiting aperture arraysubstrate 220 is provided, since the first shaping aperture arraysubstrate 230 disposed at a position closer to the electron gun 201 isfurther heated than the second shaping aperture array substrate 240, thedegree of thermal expansion becomes large. For this reason, there occurshifts of the positions of the other 24 circles 334 from the position ofthe central circle 334 a among the 25 circles 334. The shift in theposition is related to the shift in the current amount of each beam(variation). That is, the current amount of the beam associated with thecentral circle 334 a is relatively large. On the other hand, withrespect to the other beams, since a relative shift occurs in thepositional relationship between one of the first apertures 232 and oneof the second apertures 242, the current amount becomes relativelysmall.

Therefore, the irradiation time correction amount calculator 60calculates the irradiation time correction amount in the predetermineddivided region of the electron beam on the basis of the current amountof the measured electron beam. The calculated irradiation timecorrection amount is stored in the irradiation time correction amountstorage memory 142. For example, in a case where the current amount ofthe electron beam is small, the irradiation time correction amount iscalculated so that the irradiation time becomes long. In addition, in acase where the electron amount of the electron beam is large, theirradiation time correction amount is calculated so that the irradiationtime becomes short. Accordingly, it is possible to adjust the variationin current amount of the multiple beams. The above results are stored,for example, as a current map in the current map storage memory 146(S56). Thus, the adjustment of shaping is ended (S58), and writing isperformed (S60).

FIG. 11 is a conceptual diagram illustrating an example of a writingoperation on a sample in the embodiment. As illustrated in FIG. 11, thewriting region 30 of the sample is virtually divided, for example, intoa plurality of strip-shaped stripe regions 32 having a stripe shape witha predetermined width in the y direction. First, by moving the XY stage105, the irradiation region 34 capable of being irradiated with one-timeshot of the multiple beams is adjusted so as to be positioned at theleft end of the first stripe region 32 or a position of further leftside, and the writing is started. When the first stripe region 32 is tobe written, by moving the XY stage 105, for example, in the −xdirection, the writing is performed relatively in the x direction. TheXY stage 105 is, for example, continuously moved at a constant speed.After the writing of the first stripe region 32 is ended, by moving theposition of the stage in the −y direction, the irradiation region 34 isadjusted so as to be positioned at the right end of the second striperegion 32 or a position of further right side relatively in the ydirection, and in turn, by moving the XY stage 105, for example, in thex direction, the writing is performed toward the −x direction in thesame manner. As the writing is performed toward the x direction in thethird stripe region 32 and the writing is performed toward the −xdirection in the fourth stripe region 32, the writing time can beshortened by performing the writing while alternately changing thedirection. However, the writing is not limited to the case of performingthe writing while alternately changing the direction, but the writingmay be performed in the same direction when writing each stripe region32.

FIG. 12 is a view illustrating an example of an irradiation region ofthe multiple beams and writing target pixels in the embodiment. In FIG.12, a plurality of control grids 27 (design grids) which are disposed ina grid shape, for example, with a beam size pitch of the multiple beamson the sample surface are set in the stripe region 32. For example, thedisposition pitch of about 10 nm is preferred. The control grids 27become the irradiation positions of the multiple beams 20 of the design.The disposition pitch of the control grids 27 is not limited to the beamsize, but the disposition pitch may be configured with a size that canbe controlled as a deflection position of the sub-deflector 209regardless of the beam size. Then, a plurality of pixels 36 which arevirtually divided in a mesh shape with the same size as dispositionpitch of the control grids 27 are set by using each control grid 27 as acenter. Each pixel 36 becomes an irradiation unit region per beam of themultiple beams. The example of FIG. 12 illustrates a case where thewriting region of the sample is divided into a plurality of striperegions 32, for example, with a size and substantially the same widthsize capable of irradiating the irradiation region 34 (writing field) byone-time irradiation of the multiple beams in the y direction. The xdirection size of the irradiation region 34 may be defined by a valueobtained by multiplying the number of beams in the x direction to thebeam pitch in the x direction of the multiple beams 20. The y directionsize of the irradiation region 34 may be defined by a value obtained bymultiplying the number of beams in the y direction to the beam pitch inthe y direction of the multiple beams 20. In addition, the width of thestripe region 32 is not limited thereto. The size that is n times of theirradiation region 34 (n is an integer of 1 or more) is preferred. Inthe example of FIG. 12, the multiple beams of, for example, 512×512columns are illustrated as the multiple beams of 8×8 columns by omissionin illustration. Then, a plurality of pixels 28 (writing positions ofbeams) that can be irradiated with one shot of the multiple beams 20 areillustrated in the irradiation region 34. In other words, the pitchbetween adjacent pixels 28 becomes the pitch between the beams of themultiple beams on design. In the example of FIG. 12, one sub-irradiationregion 29 (beam pitch region) is configured in a square region beingsurrounded by four adjacent pixels 28 and including one pixel 28 amongthe four pixels 28. In the example of FIG. 12, illustrated is a casewhere each sub-irradiation region 29 is configured with 4×4 (=16)pixels.

Heretofore, the embodiments have been described with reference tospecific examples. However, embodiments are not limited to thesespecific examples. In addition, the portions not directly required forthe description of embodiments, such as the configuration of theapparatus and the control method, and the like have been omitted indescription. However, the configuration of the apparatus and the controlmethod to be required may be selectively used as appropriate. Forexample, although the configuration of the controller for controllingthe writing apparatus 100 is omitted in description, it is needless tosay that the required configuration of the controller may be selectivelyused as appropriate.

Besides, all the multi-charged-particle beam writing apparatuses and themulti-charged-particle beam writing methods that include the elements ofembodiments and can be appropriately modified by those skilled in theart are included within the scope of embodiments.

What is claimed is:
 1. A multi-charged-particle beam writing apparatus,comprising: an emitter emitting a charged particle beam; a first shapingaperture array substrate having a plurality of first apertures andforming first multiple beams by passing a part of the charged particlebeam through the first apertures, respectively, each of the firstapertures having a first edge; a second shaping aperture array substratehaving second apertures formed at positions corresponding to therespective first apertures and forming second multiple beams by passingat least a part of each of the first multiple beams through thecorresponding second apertures, respectively, each of the secondapertures having a second edge; a blanking aperture array having thirdapertures formed at positions corresponding to the respective secondapertures and including blankers disposed in the respective thirdapertures to perform blanking deflection on the respective beams of thecorresponding second multiple beams; a movable mechanism moving at leastone of the first shaping aperture array substrate and the second shapingaperture array substrate; a controller controlling the movablemechanism; a transmission current measurement circuit measuring acurrent of the second multiple beams transmitting respectively throughthe blanking aperture array; and an origin map storage memory storing anorigin map indicating a relative positional relationship between thefirst shaping aperture array substrate and the second shaping aperturearray substrate, the origin map being created on the basis of a resultof the measurement, wherein each of the second multiple beams is shapedby both of the first edge and the second edge.
 2. Themulti-charged-particle beam writing apparatus according to claim 1,further comprising a limiting aperture array substrate having aplurality of fourth apertures, each of the fourth apertures having asize larger than a size of each of the first apertures and forming thirdmultiple beams by passing a part of the charged particle beam throughthe fourth apertures, respectively, wherein a part of each of the thirdmultiple beams passes through the respective first apertures,respectively.
 3. The multi-charged-particle beam writing apparatusaccording to claim 1, wherein shapes of the first apertures and shapesof the second apertures are different from each other.
 4. Themulti-charged-particle beam writing apparatus according to claim 1,wherein the transmission current measurement circuit measures thecurrent of the second multiple beams transmitting respectively through aplurality of divided regions of the blanking aperture array.
 5. Themulti-charged-particle beam writing apparatus according to claim 1,further comprising an irradiation time correction amount calculatorcalculating an irradiation time correction amount for adjusting avariation in current amount of the second multiple beams on the basis ofa result of the measurement.
 6. The multi-charged-particle beam writingapparatus according to claim 5, further comprising an irradiation timecorrection amount storage memory storing the irradiation time correctionamount.
 7. The multi-charged-particle beam writing apparatus accordingto claim 6, further comprising a current map storage memory storing acurrent map with the variation in current amount of the second multiplebeams being adjusted, by using the irradiation time correction amount.8. A multi-charged-particle beam writing method, comprising: formingfirst multiple beams by allowing portions of a charged particle beam topass through a plurality of first apertures of a first shaping aperturearray substrate, respectively; forming second multiple beams by allowingat least portions of respective beams of the first multiple beams topass through a plurality of second apertures of a second shapingaperture array substrate formed at positions corresponding to the firstapertures, respectively; performing blanking deflection on therespective beams of the second multiple beams; performing measurement oftransmission current of the second multiple beams on each ofpredetermined divided regions of a blanking aperture array; and movingat least one of the first shaping aperture array substrate and thesecond shaping aperture array substrate on the basis of a result of thecurrent measurement.
 9. The multi-charged-particle beam writing methodaccording to claim 8, wherein a correction amount of irradiation time inthe predetermined divided region is calculated on the basis of a resultof the current measurement, and wherein the irradiation time of therespective beams of the second multiple beams is corrected by using thecorrection amount.
 10. The multi-charged-particle beam writing methodaccording to claim 8, further comprising forming third multiple beams byallowing portions of the charged particle beam to pass through aplurality of fourth apertures provided in a limiting aperture array,respectively, wherein at least portions of the respective beams of thethird multiple beams corresponding to the first apertures pass throughthe first apertures.
 11. The multi-charged-particle beam writing methodaccording to claim 8, wherein shapes of the first apertures and shapesof the second apertures are different from each other.
 12. Themulti-charged-particle beam writing method according to claim 8,comprising storing an origin map indicating a relative positionalrelationship between the first shaping aperture array substrate and thesecond shaping aperture array substrate, the origin map being created bythe current measurement.